A battery is a device that converts the chemical energy contained in its active materials directly into electrical energy by means of an oxidation-reduction electrochemical reaction. This type of reaction involves the transfer of electrons from one material to another. Batteries in the art commonly utilize electrochemical operations to store and release electrical energy.
FIG. 1 illustrates the electrochemical operation of a typical battery. Referring to FIG. 1, the negative electrode (anode 2) is the component capable of giving up electrons, being oxidized during the reaction. It is separated from the oxidizing material, which is the positive electrode (cathode 1), the component capable of accepting electrons. The transfer of electrons takes place in the external circuit 11 connecting the two materials and in the electrolyte 3, which provides an ionic medium for the electron transfer in the battery 4.
Certain types of batteries are rechargeable, such as lead acid batteries. A lead acid battery uses sponge lead for the negative electrode (anode 2), lead oxide for the positive electrode (cathode 1), and a sulfuric acid solution for the electrolyte 3. The lead acid battery 4 is left in a charged condition when it is not being used. During discharge, the active material in the lead acid battery is converted into lead sulfate and the sulfuric acid solution is diluted, i.e., its specific gravity decreases. Lead sulfate is an insulator that inhibits the proper charging of the lead acid battery 4. However, the lead acid battery 4 can be used after it is recharged.
To recover the lead acid battery, the lead sulfate is converted back to active material by charging the battery at a low current. If the lead acid battery is left in discharge for a long time, typically a few days, it becomes sulfated and difficult to recharge. The sulfated lead acid battery is discarded if it is not recoverable, which is wasteful and harmful to the environment.
Therefore, there is a general need in the art for an improved apparatus and method of recovering lead acid batteries. An efficient apparatus and method for recovering lead acid batteries, that avoids unnecessary waste, is needed.